Influence of processing stages on antimutagenic and antioxidant potentials of rooibos tea
Date
2001, 2001
Authors
Standley L.
Winterton P.
Marnewick J.L.
Gelderblom W.C.A.
Joubert E.
Britz T.J.
Standley L.
Winterton P.
Marnewick J.L.
Gelderblom W.C.A.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The antimutagenic and antioxidant potentials of rooibos (Aspalathus linearis) tea samples, collected from each of its major processing stages, were evaluated according to the Salmonella typhimurium mutagenicity test and the hydrogen donating ability and superoxide anion radical scavenging assays, respectively. Ten random samples were collected before and after fermentation, as well as after sun-drying, sieving, and steam pasteurization. Results indicated that the fermented tea had a significantly (P < 0.05) lower antimutagenic and antioxidant potential than the unfermented tea. Of the different processing stages, the most significant reduction in the antimutagenic and antioxidant property of the tea was found during the "fermentation" step. Sun-drying, sieving, and steam pasteurization also reduced the antimutagenic potential of the tea, although not to the same extent as the first processing step. The hydrogen donating ability was significantly increased after steam pasteurization in comparison to those of fermented and sun-dried tea. Pasteurization did not affect superoxide anion radical scavenging in comparison to fermented tea. Differences seem to exist in the antimutagenicity and antioxidant potencies of the tea sampled at the various stages during processing. A possible role of tea polyphenols in the antimutagenic and antioxidant activities of the tea is suggested as processing caused a significant reduction in the total polyphenolic content.
The antimutagenic and antioxidant potentials of rooibos (Aspalathus linearis) tea samples, collected from each of its major processing stages, were evaluated according to the Salmonella typhimurium mutagenicity test and the hydrogen donating ability and superoxide anion radical scavenging assays, respectively. Ten random samples were collected before and after fermentation, as well as after sun-drying, sieving, and steam pasteurization. Results indicated that the fermented tea had a significantly (P < 0.05) lower antimutagenic and antioxidant potential than the unfermented tea. Of the different processing stages, the most significant reduction in the antimutagenic and antioxidant property of the tea was found during the "fermentation" step. Sun-drying, sieving, and steam pasteurization also reduced the antimutagenic potential of the tea, although not to the same extent as the first processing step. The hydrogen donating ability was significantly increased after steam pasteurization in comparison to those of fermented and sun-dried tea. Pasteurization did not affect superoxide anion radical scavenging in comparison to fermented tea. Differences seem to exist in the antimutagenicity and antioxidant potencies of the tea sampled at the various stages during processing. A possible role of tea polyphenols in the antimutagenic and antioxidant activities of the tea is suggested as processing caused a significant reduction in the total polyphenolic content.
The antimutagenic and antioxidant potentials of rooibos (Aspalathus linearis) tea samples, collected from each of its major processing stages, were evaluated according to the Salmonella typhimurium mutagenicity test and the hydrogen donating ability and superoxide anion radical scavenging assays, respectively. Ten random samples were collected before and after fermentation, as well as after sun-drying, sieving, and steam pasteurization. Results indicated that the fermented tea had a significantly (P < 0.05) lower antimutagenic and antioxidant potential than the unfermented tea. Of the different processing stages, the most significant reduction in the antimutagenic and antioxidant property of the tea was found during the "fermentation" step. Sun-drying, sieving, and steam pasteurization also reduced the antimutagenic potential of the tea, although not to the same extent as the first processing step. The hydrogen donating ability was significantly increased after steam pasteurization in comparison to those of fermented and sun-dried tea. Pasteurization did not affect superoxide anion radical scavenging in comparison to fermented tea. Differences seem to exist in the antimutagenicity and antioxidant potencies of the tea sampled at the various stages during processing. A possible role of tea polyphenols in the antimutagenic and antioxidant activities of the tea is suggested as processing caused a significant reduction in the total polyphenolic content.
Description
Keywords
plant extract; polyphenol derivative; scavenger; superoxide; unclassified drug; Ames test; antioxidant activity; article; aspalathus linearis; controlled study; desiccation; fermentation; food analysis; food handling; mutagen testing; nonhuman; pasteurization; Salmonella typhimurium; tea; water vapor; 2-Acetylaminofluorene; Antimutagenic Agents; Antioxidants; Desiccation; Fermentation; Food Handling; Free Radical Scavengers; Mutagenicity Tests; Steam; Superoxides; Tea; Aspalathus linearis; Salmonella typhimurium; Typhimurium, plant extract, polyphenol derivative, scavenger, superoxide, unclassified drug, Ames test, antioxidant activity, article, aspalathus linearis, controlled study, desiccation, fermentation, food analysis, food handling, mutagen testing, nonhuman, pasteurization, Salmonella typhimurium, tea, water vapor, 2-Acetylaminofluorene, Antimutagenic Agents, Antioxidants, Desiccation, Fermentation, Food Handling, Free Radical Scavengers, Mutagenicity Tests, Steam, Superoxides, Tea, Aspalathus linearis, Salmonella typhimurium, Typhimurium
Citation
Journal of Agricultural and Food Chemistry
49
1
Journal of Agricultural and Food Chemistry
49
1
49
1
Journal of Agricultural and Food Chemistry
49
1